1) Field of the Invention
The subject invention generally relates to an optical fiber laser structure and system. More specifically, the subject invention relates to an optical fiber laser structure and system including a core element and an ASE-pumped cladding element providing laser activity at a laser wavelength of from 1500 to 1600 nanometers.
2) Description of Related Art
Optical fiber laser structures and systems are known in the art. Cladding-pumped optical fiber laser structures and systems are also known in the art. Cladding-pumped optical fiber laser structures and systems are utilized throughout the medical and telecommunication industries. More specifically, cladding-pumped optical fiber laser structures and systems have advanced the state-of-the-art in these industries by permitting pumping of single-mode core elements with multi-mode high power pumping sources. As a result, optical fiber laser structures can be developed with power densities that are only limited by material considerations and the ability to introduce energy, through the pumping sources, into the optical fiber laser structure.
One example of a cladding-pumped optical fiber laser structure and system is disclosed in U.S. Pat. No. 5,291,501. Conventional cladding-pumped optical fiber laser structures, including the cladding-pumped structure disclosed in the above-referenced patent, are deficient for various reasons. For instance, the cladding-pumped structure disclosed in the ""501 patent, and in particular the thulium-containing core element of this structure, only provides laser activity at a laser wavelength of 2 nanometers (nm). Therefore, the cladding-pumped structure disclosed in the ""501 patent has limited application as it is not suitable for providing laser activity at a laser wavelength of from 1500 to 1600 nm. The laser wavelength of from 1500 to 1600 nm is critical in the medical industry for eye-safe optical fiber laser structures and is also critical in the telecommunication industry where this wavelength is the preferred operating wavelength.
The cladding-pumped optical fiber laser structures of the prior art are also deficient because these structures rely on lasing to transfer energy to the core element. Simply stated, reliance on lasing to transfer energy to the core element is not as efficient as utilizing amplified spontaneous emission to transfer the energy to the core element.
Due to the deficiencies identified in the cladding-pumped optical fiber laser structures of the prior art, including those set forth above, it is desirable to implement an optical fiber laser structure and system including a core element and an ASE-pumped cladding element providing laser activity at a laser wavelength of from 1500 to 1600 nanometers.
An optical fiber laser structure and system are disclosed. The optical fiber laser structure includes a core element and a cladding element. The core element has a first and second end. The core element includes a first active gain component. The cladding element at least partially surrounds the core element. The cladding element has a length defined between the first and second ends of the core element.
The cladding element includes a second active gain component that is different from the first active gain component. The second active gain component is suitable for achieving amplified spontaneous emission (ASE) in the cladding element. More specifically, the second active gain component is suitable for achieving ASE in the cladding element along the length between the first and second ends of the core element. As a result, energy is efficiently transferred to the first active gain component in the core element to provide laser activity at a laser wavelength of from 1500 to 1600 nanometers. The optical fiber laser system of the subject invention additionally includes a pumping source. The pumping source is coupled to the cladding element to provide the energy to the cladding element such that the second active gain component achieves the ASE.
Accordingly, the subject invention provides an optical fiber laser structure and system including a core element and an ASE-pumped cladding element that provides laser activity at a laser wavelength of from 1500 to 1600 nanometers.